#pragma once
#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<assert.h>
#include<stdbool.h>
using namespace std;
class Date
{
	friend ostream& operator<<(ostream& out, const Date& d);
	friend istream& operator>>(istream& in, Date& d);
public:
	Date(int year = 2000, int month = 1, int day = 1);
	void Print()
	{
		cout << _year << "/" << _month << "/" << _day << endl;
	}
	int GetMonthDay(int year, int month)
	{
		assert(month > 0 && month < 13);
		static int arr[] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
		if (month == 2 && (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0))
		{
			return 29;
		}
		return arr[month];
	}
	bool CheckDate()
	{
		if (_month < 1 || _month > 12 || _day < 1 || _day > GetMonthDay(_year, _month))
		{
			return false;
		}
		return true;
	}
	Date& operator+=(int day);
	Date operator+(int day);
	Date& operator-=(int day);
	int operator-(const Date& d);
	bool operator<(const Date& d);
	bool operator==(const Date& d);
	bool operator!=(const Date& d);
private:
	int _year;
	int _month;
	int _day;
};
ostream& operator<<(ostream& out, const Date& d);
istream& operator>>(istream& in, Date& d);